MESOSCALE DISCUSSION 0850
   NWS STORM PREDICTION CENTER NORMAN OK
   0251 PM CDT MON MAY 21 2007
   
   AREAS AFFECTED...SWRN TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 211951Z - 212115Z
   
   STORMS ARE EXPECTED TO FORM BETWEEN 20-21Z AND WILL POSE A THREAT OF
   VERY LARGE HAIL AS WELL AS GUSTY WINDS. A WW IS LIKELY BEFORE 21Z.
   
   VISIBLE IMAGERY SHOWS TCU DEVELOPING OVER THE HIGH TERRAIN WHERE
   HEATING HAS ERODED CIN. MEANWHILE...SELY LOW LEVEL FLOW WILL
   MAINTAIN 50S DEWPOINTS INTO THE REGION. FLOW ALOFT WEAKENS WITH NWD
   EXTENT...BUT IS SUFFICIENT FOR SUPERCELLS MAINLY SRN AREAS. MOIST
   AREA ON WATER VAPOR IMAGERY AND OBJECTIVELY ANALYZED MID LEVEL COOL
   POCKET WILL FURTHER CONDITION THE ENVIRONMENT FOR SUCCESSFUL SEVERE
   STORM FORMATION. THE STRONGEST STORMS WILL LIKELY BECOME SUPERCELLS
   BY LATE AFTERNOON AND WILL TRAVEL IN A SELY DIRECTION WITH A THREAT
   OF 2.00+ INCH HAIL.
   
   ..JEWELL.. 05/21/2007
   
   
   ATTN...WFO...EWX...SJT...MAF...
   
   29600276 30150413 30830384 31370364 31820316 31930192
   31550054 30699982 30219984 29630127 29830191 29710276